The aim of this study was to perform comparative gene expression analysis of AIP mutation-positive, AIP mutation-negative familial and sporadic somatotroph tumours to discover the genes/pathways responsible for the aggressive phenotype.
Multi-chaperone function modulation and association with cytoskeletal proteins are key features of the function of AIP in the pituitary gland.
No sample metadata fields
View SamplesThis series includes the four major subtypes of pituitary adenomas and normal post-mortem pituitary tissue
Differential gene expression in pituitary adenomas by oligonucleotide array analysis.
No sample metadata fields
View SamplesPheochromocytomas are neural crest-derived tumors that arise from inherited or sporadic mutations in at least six independent genes: RET, VHL, NF1, and subunits B, C and D of succinate dehydrogenase (SDH). The proteins encoded by these multiple genes regulate distinct functions. To identify molecular interactions between the distinct pathways we performed expression profiling of a large cohort of pheochromocytomas. We show here a functional link between tumors with VHL mutations and those with disruption of the genes encoding for succinate dehydrogenase (SDH) subunits B (SDHB) and D (SDHD). A transcription profile of reduced oxidoreductase is detected in all three of these tumor types, together with an angiogenesis/hypoxia profile typical of VHL dysfunction. The oxidoreductase defect, not previously detected in VHL-null tumors, is explained by suppression of the SDHB protein, a component of mitochondrial complex II. The decrease in SDHB is also noted in tumors with SDHD mutations. Gain-of-function and loss-of-function analyses show that the link between hypoxia signals (via VHL) and mitochondrial signals (via SDH) is mediated by HIF1?. These findings explain the shared features of pheochromocytomas with VHL and SDH mutations and suggest an additional mechanism for increased HIF1? activity in tumors.
A HIF1alpha regulatory loop links hypoxia and mitochondrial signals in pheochromocytomas.
Specimen part
View SamplesPositioned nucleosomes limit the access of proteins to DNA and implement regulatory features encoded in eukaryotic genomes. Here we generated the first genome-wide nucleosome positioning map for Schizosaccharomyces pombe and annotated transcription start and termination sites genome-wide. Using this resource we found surprising differences compared to the nucleosome organization in the distantly related yeast Saccharomyces cerevisiae [the cerevisiae data has been published by others (PMID: 17873876) and the raw data is deposited at ArrayExpress(E-MEXP-1172)]. DNA sequence guides nucleosome positioning differently, e.g., poly(dA:dT) elements are not enriched in S. pombe nucleosome-depleted regions (NDRs). Regular nucleosomal arrays emanate more asymmetrically, i.e., mainly co-directionally with transcription, from promoter NDRs, but promoters harbouring the histone variant H2A.Z show regular arrays also upstream. Regular nucleosome phasing in S. pombe has a very short repeat length of 154 base pairs, and requires a remodeler, Mit1, conserved in humans but not found in S. cerevisiae. Nucleosome positioning mechanisms are evidently not universal but evolutionarily plastic.
Schizosaccharomyces pombe genome-wide nucleosome mapping reveals positioning mechanisms distinct from those of Saccharomyces cerevisiae.
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View SamplesInhibition of Brd4 with Jq1 in neurons with or without BDNF stimulation Overall design: Examination of the effects of Jq1 treatment on primary mouse cortical neurons
BET protein Brd4 activates transcription in neurons and BET inhibitor Jq1 blocks memory in mice.
No sample metadata fields
View SamplesIdentifying the genes underlying quantitative trait loci (QTL) for disease has proven difficult, mainly due to the low resolution of the approach and the complex genetics involved. However, recent advances in bioinformatics and the availability of genetic resources now make it possible to narrow the genetic intervals and test candidate genes. In addition to identifying the causative genes, defining the pathways that are affected by these QTL is of major importance as it can give us insight into the disease process and provide evidence to support candidate genes. In this study we mapped three significant and one suggestive QTL on Chromosomes (Chrs) 1, 4, 15, and 17, respectively, for increased albumin excretion (measured as albumin-to-creatinine ratio) in a cross between the MRL/MpJ and SM/J mouse inbred strains. By combining data from several sources and by utilizing gene expression data, we identified Tlr12 as a likely candidate for the Chr 4 QTL. Through the mapping of 33,881 transcripts measured by microarray on kidney RNA from each of the 173 male F2 animals, we identified several downstream pathways associated with these QTL. Among these were the glycan degradation, leukocyte migration, and antigen presenting pathways. We demonstrate that by combining data from multiple sources, we can identify not only genes that are likely to be causal candidates for QTL, but also the pathways through which these genes act to alter phenotypes. This combined approach provides valuable insights into the causes and consequences of renal disease.
Uncovering genes and regulatory pathways related to urinary albumin excretion.
Sex, Age
View SamplesWidespread epigenetic disruptions in FXS mice leads to transcriptional changes that likely contribute to the neuronal phenotpyes underlying FXS. Overall design: 7DIV cultured cortical neurons from WT or Fmr1 KO mice were treated for 24 hours with vehicle, Jq1, or THZ, performed in triplicate.
Excess Translation of Epigenetic Regulators Contributes to Fragile X Syndrome and Is Alleviated by Brd4 Inhibition.
Treatment, Subject
View SamplesWe examined genome-wide variation in transcription factor binding in different individuals and a chimpanzee using chromatin immunoprecipitation followed by massively-parallel sequencing (ChIP-Seq). The binding sites of RNA Polymerase II (Pol II) as well as a key regulator of immune responses, NFkB, were mapped in ten HapMap lymphoblastoid cell lines derived from individuals of African, European, and Asian ancestry, including a parent-offspring trio. We also mapped gene expression in all ten human cell lines for two treatment conditions: a) no treatment and b) following induction by TNF-alpha. Overall design: Genome-wide comparison of Pol II and NF-KappaB binding in ten individuals. RNA-seq study with no treatment.
Variation in transcription factor binding among humans.
No sample metadata fields
View SamplesWe examined genome-wide variation in transcription factor binding in different individuals and a chimpanzee using chromatin immunoprecipitation followed by massively-parallel sequencing (ChIP-Seq). The binding sites of RNA Polymerase II (Pol II) as well as a key regulator of immune responses, NFkB, were mapped in ten HapMap lymphoblastoid cell lines derived from individuals of African, European, and Asian ancestry, including a parent-offspring trio. We also mapped gene expression in all ten human cell lines for two treatment conditions: a) no treatment and b) following induction by TNF-alpha. Overall design: Genome-wide comparison of Pol II and NF-KappaB binding in ten individuals. RNA-seq study with TNF-alpha treatment.
Variation in transcription factor binding among humans.
No sample metadata fields
View Samples18 zero-hour and 18 selected post-transplant (Tx) biopsy samples from 18 kidney allografts (8 acute kidney injury (AKI), 10 PBx - protocol biopsies - controls) were analyzed by using the Affymetrix GeneChip Human Gene 2.0 ST Array.
Molecular biomarker candidates of acute kidney injury in zero-hour renal transplant needle biopsies.
Specimen part
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